Professional Live Sound
System Analysis

Live Sound System Analysis: The Modern Approach to System Optimization

Live sound engineering has always been a discipline where objective measurement separates professional results from guesswork. The transfer function — the frequency-domain ratio of what comes out of the loudspeaker system to what goes in — is the fundamental measurement for system optimization. It reveals magnitude response deviations that indicate EQ issues, phase response anomalies that suggest delay misalignment between components, and coherence drops that expose comb filtering, reflections, or signal-to-noise problems. For decades, this measurement required Smaart ($899), a multi-channel audio interface ($300-$1,500), a calibrated measurement microphone ($100-$500), and a laptop — a minimum investment of $1,300 that placed professional system analysis out of reach for most working sound engineers.

Transfer Function Measurement Without the Gear

SonaVyx implements the same dual-channel FFT analysis used by professional measurement platforms, but runs entirely in the web browser using Rust compiled to WebAssembly for near-native DSP performance. The H1 estimator H(f) = Gxy(f) / Gxx(f) provides the frequency response of the system under test, where Gxy is the cross-spectral density between the reference and measurement signals, and Gxx is the auto-spectral density of the reference. Welch's method provides spectral averaging with configurable 50% or 75% overlap, reducing variance in the estimate while maintaining frequency resolution. The magnitude-squared coherence function provides a quality metric at each frequency bin, indicating whether the measured response is dominated by the direct signal (high coherence) or by noise and reflections (low coherence). Phase is unwrapped and displayed alongside group delay, enabling precise identification of delay offsets between loudspeaker components — critical for subwoofer-to-main alignment and fill speaker timing.

AI-Powered Diagnostics: Beyond the Trace

Where traditional measurement platforms stop at displaying data, SonaVyx adds an intelligence layer. The AI diagnostic engine, powered by Claude, analyzes the complete measurement dataset — magnitude response, phase response, coherence, and impulse response — and provides specific, actionable recommendations. Instead of staring at a coherence dip at 2.5 kHz and mentally calculating potential causes, the AI identifies the likely source (e.g., a 0.4ms delay offset suggesting a 34cm path length difference between two sources), proposes the fix (e.g., "add 0.4ms delay to the downfill to align with the main array at the crossover point"), and estimates the expected improvement. This transforms measurement from a specialist skill requiring years of pattern-recognition experience into an accessible tool that any competent sound engineer can use effectively.

Real-Time Problem Detection

The problem detector runs continuously during measurement, analyzing the data stream for common system issues. Feedback loop detection identifies narrowband peaks with high coherence that indicate potential feedback frequencies before they become audible. Comb filtering detection flags the characteristic periodic notch pattern caused by time-offset signal summation, distinguishing between acoustic reflections (which require treatment or listener position changes) and electrical summation issues (which require delay adjustment or polarity correction). Polarity inversion detection compares the impulse response polarity and phase response trend across the passband to identify drivers or signal paths that are wired out of polarity. Each detected issue is tagged with a severity level, the affected frequency range, and a recommended corrective action.

Multi-Device Measurement via WebSocket

Traditional dual-channel measurement requires both the reference signal and the microphone signal to arrive at the same physical device via an audio interface. SonaVyx eliminates this requirement using WebSocket communication between two smartphones on the same network. One device acts as the source, generating the test signal (pink noise, log sweep, or pass-through from the console output) and playing it through the sound system. The second device captures the microphone input at the measurement position. NTP-synchronized timestamps ensure sample-accurate alignment between the two data streams. The session pairing system uses 6-digit room codes for quick connection, with device roles (source/listener) and capabilities negotiated automatically. This two-phone approach means you can measure the system from any position in the venue while the source device stays connected at front-of-house — no long microphone cables, no audio interface, no laptop.

Who Uses SonaVyx for Live Sound?

SonaVyx serves the full spectrum of live sound professionals. Freelance sound engineers use it as a portable measurement tool that is always in their pocket, ready for soundcheck optimization at any venue. System technicians for touring productions use it for quick verification measurements when the main Smaart rig is in the truck or when checking fills and delays in locations where running cable is impractical. AV integrators use it for commissioning installed systems in houses of worship, conference centers, and performance venues, generating the documentation required for client handoff. Rental companies use it for quality assurance on speaker cabinets and amplifier racks before they ship. In every case, the value proposition is the same: professional-grade measurement results without the cost, complexity, and logistics of traditional measurement equipment.